Application of intravascular ultrasound in stent implantation for coronary artery disease

Objective To investigate the function of intravascular ultrasound (IVUS) in stent implantation for treatment of coronary heart disease. Methods Qualitative and quantitative analysis was done in 50 coronary artery disease patients with 52 lesions before and after stent implantation. The stent diameter and the end point of therapy determined by IVUS standard. The difference of end point for stent implantation guided by CAG and by IVUS was analyzed and the enlargement of lumen area gained by stent implantation was compared in the two groups, the mechanism of lumen enlargement was analyzed. Results The average stent diameter guided by IVUS was larger than that guided by CAG [(3.48±0.29) mm vs (3.36±0.33) mm, P=0.011], the peak balloon pressure was higher in IVUS group than CAG group [(17.7±2.9) atm vs (12.8?a2.4) atm, P￡1/40.001], and area stenosis percentage measured by quantitative coronary angiogram was smaller in IVUS group than CAG group [(13.2±6.6)% vs (16.6±9.1%), P=0.044]. CAG showed the success rate was 96.2% and IVUS showed the success rate was only 37.7% after first balloon high-pressure dilation. IVUS subgroup analysis showed the peak balloon pressure was higher [(116.13±1.87) atm vs (12.62?a2.61) atm, P￡1/40.001], lumen diameter was larger [(3.64?a0.53) mm vs (3.31?a0.57) mm, P￡1/40.001], lumen area was larger [(9.90±2.05) mm2 vs (8.84?a1.67) mm2, P￡1/40.001], and area stenosis percentage was smaller (49.15%?a9.03% vs 54.24%?a10.05%, P￡1/40.001]. There was no obvious stenosis at proximal and distal segment to the stent observed by CAG, while there were 39 (75.0%) atherosclerotic lesions at proximal segment to the stent and 23 (44.2%) atherosclerotic lesioos at distal to the stent observed by IVUS. The lumen area was larger [(4.50?a1.67) mm2 vs (3.68?a0.97) mm2, P￡1/40.001] in fatty plaque than in non-fatty plaque after stent implantation. Compared with non-fatty plaque, the enlargement of vessel area was 1.30 mm2 smaller, while plaque compression was 0.48 mm2 larger. Conclusion Compared with CAG, IVUS can identified the quality of plaque more precisely and help choose stent more objectively; larger lumen area and smaller area stenosis percentage can be gained under IVUS guidance.